Trump tried to rally Republican lawmakers behind a plan to dismantle Obamacare on Tuesday, with moderate Republicans worrying that millions of Americans will be hurt by the dismantling of former President Barack Obama's signature healthcare legislation, while conservative lawmakers believe the healthcare bill does not go far enough.

Investors worry a failed healthcare push could also portend trouble for Trump's promise to cut taxes and ease regulation that have propelled the market to record highs in recent months.

Regional stock markets are down with "the surprise 200-point drop" in U.S. equities, said Joseph Roxas, president of Manila-based Eagle Equities Inc.

In Singapore, shares closed 1.3% lower, their third consecutive session of losses, led by energy stocks as global oil prices dipped on rising crude inventory in the United States.